/*
 Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 

  The MySQL Connector/J is licensed under the terms of the GPLv2
  <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most MySQL Connectors.
  There are special exceptions to the terms and conditions of the GPLv2 as it is applied to
  this software, see the FLOSS License Exception
  <http://www.mysql.com/about/legal/licensing/foss-exception.html>.

  This program is free software; you can redistribute it and/or modify it under the terms
  of the GNU General Public License as published by the Free Software Foundation; version 2
  of the License.

  This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the GNU General Public License for more details.

  You should have received a copy of the GNU General Public License along with this
  program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth
  Floor, Boston, MA 02110-1301  USA

 */

package com.mysql.jdbc;

import java.sql.SQLException;
import java.sql.SQLClientInfoException;
import java.util.Properties;



/**
 * Classes that implement this interface and provide a no-args constructor
 * can be used by the driver to store and retrieve client information and/or
 * labels.
 * 
 * The driver will create an instance for each Connection instance, and call
 * initialize() once and only once. When the connection is closed, destroy()
 * will be called, and the provider is expected to clean up any resources at
 * this time.
 *
 * @version $Id: $
 */
public interface JDBC4ClientInfoProvider {
	/**
	 * Called once by the driver when it needs to configure the provider.
	 * 
	 * @param conn the connection that the provider belongs too.
	 * @param configurationProps a java.util.Properties instance that contains
	 * configuration information for the connection. 
	 * @throws SQLException if initialization fails.
	 */
	public void initialize(java.sql.Connection conn, Properties configurationProps) throws SQLException;
	
	/**
	 * Called once by the driver when the connection this provider instance
	 * belongs to is being closed.
	 * 
	 * Implementations are expected to clean up and resources at this point
	 * in time.
	 * 
	 * @throws SQLException if an error occurs.
	 */
	public void destroy() throws SQLException;
	
	/**
	 * Returns the client info for the connection that this provider
	 * instance belongs to. The connection instance is passed as an argument
	 * for convenience's sake.
	 * 
	 * Providers can use the connection to communicate with the database,
	 * but it will be within the scope of any ongoing transactions, so therefore
	 * implementations should not attempt to change isolation level, autocommit settings
	 * or call rollback() or commit() on the connection.
	 * 
	 * @param conn
	 * @return 
	 * @throws SQLException
	 * 
	 * @see java.sql.Connection#getClientInfo()
	 */
	public Properties getClientInfo(java.sql.Connection conn) throws SQLException;

	/**
	 * Returns the client info for the connection that this provider
	 * instance belongs to. The connection instance is passed as an argument
	 * for convenience's sake.
	 * 
	 * Providers can use the connection to communicate with the database,
	 * but it will be within the scope of any ongoing transactions, so therefore
	 * implementations should not attempt to change isolation level, autocommit settings
	 * or call rollback() or commit() on the connection.
	 * 
	 * @param conn
	 * @return 
	 * @throws SQLException
	 * 
	 * @see java.sql.Connection#getClientInfo(java.lang.String)
	 */
	public String getClientInfo(java.sql.Connection conn, String name) throws SQLException;
	
	/**
	 * Sets the client info for the connection that this provider
	 * instance belongs to. The connection instance is passed as an argument
	 * for convenience's sake.
	 * 
	 * Providers can use the connection to communicate with the database,
	 * but it will be within the scope of any ongoing transactions, so therefore
	 * implementations should not attempt to change isolation level, autocommit settings
	 * or call rollback() or commit() on the connection.
	 * 
	 * @param conn
	 * @return 
	 * @throws SQLException
	 * 
	 * @see java.sql.Connection#setClientInfo(java.util.Properties)
	 */
	public void setClientInfo(java.sql.Connection conn, Properties properties) throws SQLClientInfoException;

	/**
	 * Sets the client info for the connection that this provider
	 * instance belongs to. The connection instance is passed as an argument
	 * for convenience's sake.
	 * 
	 * Providers can use the connection to communicate with the database,
	 * but it will be within the scope of any ongoing transactions, so therefore
	 * implementations should not attempt to change isolation level, autocommit settings
	 * or call rollback() or commit() on the connection.
	 * 
	 * @param conn
	 * @return 
	 * @throws SQLException
	 * 
	 * @see java.sql.Connection#setClientInfo(java.lang.String,java.lang.String)
	 */
	public void setClientInfo(java.sql.Connection conn, String name, String value) throws SQLClientInfoException;
}
